Studying Space Dust

NASA spacecraft provides field samples for Dartmouth researchers

When you work with space dust, it can be difficult to collect field data. Luckily for some Dartmouth researchers, NASA's Stardust spacecraft has recently returned to Earth, after a seven-year voyage, with some samples to study.

Taylor expects her samples will arrive in a few months. The research is part of the effort to learn more about comets and other interstellar particles to better understand how our universe was made and what it's made of.

"We want to learn how it formed, why it formed, and what's happened since," she says. "This will help us piece together the story of our solar system"

Taylor is working with Charles Daghlian, director of Dartmouth's Electron Microscope Facility, and intern Emily Koepsell '09 on "bulk analysis." In other words, they will examine the larger chunks captured by Stardust, which only measure about 20 to 50 microns across, less than the thickness of a piece of paper. About 160 research teams worldwide are looking at the Stardust particles, and Taylor and Daghlian are part of the bulk chemistry examination group.

Koepsell, a participant in Dartmouth's Women in Science Project (WISP) will be assisting Taylor and Daghlian. She started her internship in January, and has been learning how to use the scanning electron microscope (SEM), a piece of equipment that uses electrons to create detailed 3-D images of very tiny items.

"When WISP announced its internships, this specific project jumped out at me because it sounded unique and involved the use of a piece of technology that I may never otherwise have the chance to operate," says Koepsell. "I love running the SEM, and I have learned how to take photos of the micrometeorites, do elemental analyses on them, and classify them based on their composition and structure."

Daghlian explains that he has been working with Taylor to co-sponsor WISP interns for at least ten years. The instrumentation he oversees has been useful in examining material for Taylor's more Earthly research endeavor: studying micrometeorites collected from the drinking water at the South Pole. Koepsell's internship includes helping analyze the South Pole micrometeorite samples that will be compared to the material from space.

Stardust flew in the wake of a comet called Wild 2, and the samples were captured using a new material called aerogel. Also called solid smoke, aerogel was specifically designed to slow down, cushion, and store the material from the comet's tail that hits the aerogel at a speed of five kilometers per second (more than 11,000 miles per hour).

"Susan and I planned to have our WISP intern working on the micrometeorites," says Daghlian, "so it was natural to extend Emily's work to include participation in the Stardust project. It's a great experience for her."